You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.

weewx
5.0.0rc3

This version was deleted from PyPI around 2024-07-05. Installing fails with:
$ pip3 install weewx==5.0.0rc3 ERROR: Could not find a version that satisfies the requirement weewx==5.0.0rc3
View other deleted versions of weewx

Install through StableBuild

You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
pip3 install \ -i https://YOUR_API_KEY.pypimirror.stablebuild.com/2024-07-04/ \ weewx==5.0.0rc3
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)

Or, download files manually

And install manually via pip:
weewx-5.0.0rc3-py3-none-any.whl (1.4MB)
weewx-5.0.0rc3.tar.gz (1.2MB)